The present invention relates in general to thickening agents based upon polyether esters, and more particularly, to topical preparations prepared therefrom.
Thickening agents are used for the thickening of natural and synthetic oils, aqueous electrolyte solutions, and aqueous solutions of organic substances. Their use facilitates the handling of liquids used as household chemicals. Thickening agents are also customarily used in electrolyte solutions, which are required in batteries. Heretofore, waxes, carboxyalkyl celluloses, starch, xanthan gum, or high-molecular esters have been used as thickening agents.
It is customary to use thickening agents for cosmetic, detergent-containing preparations, e.g., shampoos, so as to stabilize the disperse systems and for better handling during use. In the case of ether sulfates, it is customary to thicken the preparations with inorganic electrolytes, preferably with common salt. In the case of other detergents, use is, for example, made of distearyl polyglycolester, cellulose derivatives, or natural and synthetic soluble polymers. The preparations obtained in this manner exhibit a behavior that is structurally viscous and/or thixotropic.
The formulation of shampoos necessitates a trade off between two conflicting physical properties. On the one hand, consumer conception demands a higher viscosity product, while on the other hand, economics require a product low in solid content. Typically, today's shampoos have a solid content in the range of 6 to 18 percent. Long chain polyethers containing a fatty moiety at one or both ends of the ether chain have been used as viscosity modifying agents in surfactant systems in the formulation of shampoo compositions. Specific viscosity modifying agents used in shampoo compositions have included PPG-5-Ceteth-20, and particularly, PEG 150 Distearate (aka. PEG 6000 Distearate), available from Witco. These agents distinguish themselves from other classes of cosmetic thickening agents by their low reactivity, low toxicity and usefulness over a broad pH range. These thickening agents are, however, linear in secondary structure and are able to fold over upon themselves thereby limiting their tendency to behave in a manner characteristic of long chain polymers. In addition, PEG 6000 Distearate is difficult to manufacture, often forming molecules having a different structure from batch to batch, i.e., containing free stearic acid, distearates and monostearates.
In Seibert et al., U.S. Pat. No. 4,774,017 there is disclosed a thickening agent comprising polyether compounds of the formula: ##STR3## These polyether derivatives are prepared by the addition of long chain 1,2-epoxy compounds having a chain length of 10 to 32 carbon atoms to either a polyethylene glycol monoether having an average molecular weight of 800 to 5,000 (the monoether group has a substituted or unsubstituted hydrocarbon radical having at least 10 carbon atoms), or to a polyethylene glycol-polypropylene glycol monoether with an average molecular weight of 850 to 6,300 (having repeating ethylene oxide and propylene oxide units each forming a polyethylene glycol and polypropylene glycol block) in which the monoether group forms the end of the polyethylene glycol block.
In Perner et al., U.S. Pat. No. 4,239,641, there is disclosed a method for regulating the viscosity of aqueous slurries of detergents and cleansers by adding to the slurries viscosity regulators, such as dihydric, trihydric or tetrahydric aliphatic alcohols, monobasic aliphatic carboxylic acids, hydroxycarboxylic acids, esters of the same alcohols, and the same acids or compounds in which the alcohols, carboxyl gases, hydroxycarboxyl acids and the individual components of the esters are from 5 to 9 carbon atoms, one of which is a quaternary carbon atom. The alcohols and hydroxycarboxylic acids contain exclusively primary alcohol groups and the carboxylic acids and the hydroxycylic acids have the carboxyl group bonded to the quaternary carbon atom.
In Gazzani et al., U.S. Pat. No. 4,774,016, there is disclosed aqueous preparations for the cleaning of skin, scalp and hair. The emulsifying agent used is selected from the group polyoxyethylenethers of higher alcohols having 10 to 40 and preferably 15 to 25 oxyethylene groups. Examples of suitable higher alcohols preferably containing 12 to 18 carbon atoms comprises lauryl, myristyl cetyl, stearyl, oleyl alcohols and cholesterol. An example of this preparation includes 1% carboxymethylcellulose, 9% polyoxyethylate ricinoleic glyceride 40, 1.5% polyoxyethylene cholesterol 24, and water. In other preparations, polyoxyethylene lauryether, polyoxyethylene sorbitan monolaurate, and polyethylene glycol 100 are used.
In Cuscurida et al., U.S. Pat. No. 4,488,982, there is disclosed low foaming, non-ionic polyether polycarbonate surfactants. Specifically disclosed is the preparation of monohydric polyether polycarbonate materials by reacting a monofunctional initiator with an alkaline carbonate or with an alkaline oxide and carbon dioxide to form polyether polycarbonate materials.
In Pader, U.S. Pat. No. 4,364,837, there is disclosed shampoo compositions including a water-miscible saccharide, water, a non-ionic or cationic hair grooming agent, and an anionic detergent. The hair grooming agents include cationic polyamide polymers such as low molecular weight adipic acid/diethylenetrimiamine polyamides and the copolymers of vinylpyrrolidone and dimethylaminoethyl methacrylate quaternized with diethyl sulfate as described in U.S. Pat. No. 4,080,310, the graphed cationic copolymer containing N-vinylpyrrolidone, dimethylaminoethyl methacrylate and polyethylene glycol described in U.S. Pat. No. 4,048,301, the mineral acid salts of the amino-alkyl esters of homo- and copolymers of unsaturated carboxylic acids having from 3 to 5 carbon atoms described in U.S. Pat. No. 4,009,256, the long-chain polymeric quaternary ammonium salts described in U.S. Pat. No. 3,990,991, the quaternary nitrogen-containing cellulose ethers described in U.S. Pat. No. 3,962,418 and the copolymers and etherified cellulose and starch described in U.S. Pat. No. 3,958,581.
Anionic detergents used include sodium lauryl sulfate, sodium oleyl succinate, ammonium lauryl sulfosuccinate, sodium lauryl ether sulfate, ammonium lauryl sulfate, sodium dodecylbenzene sulfinate, triethanolamine dodecylbenzene sulfinate, and sodium N-lauryl sarcosinate. The amphoteric or amphoyltic detergents include N-lauryl-N,carboxymethyl-N-(2-hydroxyethyl) ethylenediamine, cocobetaine, and the Miranol compounds in U.S. Pat. Nos. 2,528,378 and 2,781,354. Other amphoteric detergents include quaternary cycloimidates, betaines, and sultaines disclosed in U.S. Pat. No. 3,964,500. Preferred thickeners are carboxymethyl cellulose, methyl cellulose, hydroxypropyl cellulose, Carbopols (Goodrich Company), vegetable gums, alginates and derivatives and latexes. In addition, amides may be used to obtain specific foam characteristics and to thicken the shampoo. Suitable amides include coconut fatty acids, diethanolamides, lauric isopropanolamides and others.
In Grote, U.S. Pat. No. 4,741,855, there is disclosed a shampoo composition comprising synthetic surfactants selected from the group of anionic surfactants, zwitterionic surfactants, amphoteric surfactants and mixtures thereof, insoluble non-volatile silicone, a long-chain (C.sub.16 to C.sub.22) acyl derivative or a long-chain (C.sub.16 to C.sub.22) amine oxide selected from the group consisting of ethylene glycol, long-chain esters, alkanol amides of long-chain fatty acids, long-chain esters of long-chain fatty acids, glyceryl long-chain esters, long-chain esters of long-chain alkanolamides, long-chain alkyl dimethyl amine oxides, mixtures thereof, and water.
In Hott et al., German Patent Application No. DE 37 26015 Al, there is disclosed reversible heat sensitive recording materials. Some of the compounds disclosed herein include pentaerythritol monostearate 78-42-2, pentaerythritol tetrastearate 115-86-6, petnaerythritol monolaurate 13057-50-6, pentaerythritol tetralaurate 13081-97-5, pentaerythritol distearate 14117-96-5, pentaerythritol monopalmitate 17661-50-6, pentaerythritol tetrapalmmitate 20753-89-3, pentaerythritol dilaurate 25354-61-4, pentaerythritol dipalmitate 26040-98-2, pentaerythritol tristearate 28553-12-0, pentaerythritol trilaurate 68258-72-0, and pentaerythritol dibehenate 68818-69-9.
In Maeda et al., Japanese Patent Application No. JP 61/207358 A2, there is disclosed esterification of alcohols with carboxylic acids in the presence of metal chloride and alkali, e.g., KOH, NaOH, K.sub.2 CO.sub.3, Na.sub.2 CO.sub.3, gave light colored and chlorine-free esters with good stability towards oxidation, being useful as plasticizers, lubricants and surfactants. A 1:4.20 mixture of pentaerythritol and caproic acid containing 0.1 molecular percent KOH and 0.1 molecular percent SnCl.sub.2 to the acid was heated to give tetra-O-caproylpentaerythritol. Also disclosed are caproic acid reactions with esterification reactions of pentaerythritol and glycerine reactions with trimethylolpropane, pentaerythritol, and neopentylglycol.
Accordingly, there is an unsolved need for a new class of thickening agents based upon polyether esters which have low reactivity, low toxicity and which are useful over a broad pH range.